Product Overview

The Allen-Bradley 1785-V40L is a specialized VME-based processor card from the PLC-5 family, engineered to integrate powerful programmable control logic directly into a VMEbus backplane. This module allows industrial users to combine the reliability of Allen-Bradley control architecture with the high-speed data processing capabilities of VME-based systems. It is particularly effective for high-level data exchange between controllers, utilizing specific MG (Message) data types for synchronized communication.

Equipped with 48,000 words of user memory and a VME interface speed of 64 KB, the 1785-V40L facilitates complex logic execution and substantial data logging. While this model was officially discontinued on July 31, 2011, it remains a critical component for maintaining and upgrading legacy VME-integrated control systems in manufacturing and specialized research environments.

Technical Specifications and Connectivity

The 1785-V40L architecture is defined by its extensive port density and diagnostic capabilities, ensuring high system visibility and expansive I/O reach.

• Memory Capacity: 48,000 words (48k) user memory; requires an external memory module for full operation.

• VMEbus Compatibility: Designed for standard VMEbus racks; facilitates high-speed peer-to-peer data transfers.

• Network Interfaces: 4 dedicated Data Highway Plus (DH+) ports and 1 Remote I/O (RIO) port.

• I/O Support: Capable of managing up to 15 I/O racks with a maximum of 120 I/O points.

• Communication Channels: Includes two remote I/O scanner channels, one extended local I/O scanner channel, and a dedicated serial port channel (RS-232, RS-422, and RS-423).

• Status Indicators: Front-panel LEDs for Battery health, RUN/FAULT status, I/O Forces, and individual channel activity (ACTIVE/FAULT).

• Physical Weight: 0.72 kg (approx. 1.55 lbs).

Applications and System Integration

The 1785-V40L is primarily utilized in hybrid environments where standard PLC logic must interface with specialized VMEbus computers or motion controllers.

• VMEbus Integration: Direct mounting into VME chassis for high-speed communication with third-party VME cards.

• Distributed Control: Managing multiple Remote I/O racks across large-scale industrial plants using DH+ networking.

• Legacy System Maintenance: Essential for the repair and sustainment of vintage automotive and aerospace assembly lines.

• Data Acquisition: Serving as a bridge for complex data sets requiring the robust instruction set of the PLC-5 platform within a VME environment.